Welcome Ericka.
I prefer fragrance flower. Plumeria are common cemetary tree here. They looks beautifull and have a sweet fragrance.
I plant cananga odorata tree and polianthes tuberosa on my mom cemetary. Both have nice fragrance when flower.
If you want them to be in container and only get watered once a week, and you said the place is mostly sun, so it should be the dry tolerant plants that can fit. White rose and lavender could be nice. But i am not sure if they can deal with once a week watering. Are rain come down often there ?
Maybe purslane will be fit. Sun loving and dry tolerant and come in many colors. Although they lack the fragrance.
